IBInspectable for Rounded and Gradient UIView

RoundedandGradient.swift

import UIKit
@IBDesignable
class CustomView: UIView {

    var fromColor: UIColor?
    var toColor: UIColor?
    var gradientLayer: CAGradientLayer?
    
   
    
    @IBInspectable var cornerRadius: CGFloat = 0 {
        didSet {
            layer.cornerRadius = cornerRadius
            layer.masksToBounds = cornerRadius > 0
        }
    }
    
    @IBInspectable var topColor: UIColor? {
        didSet {
            fromColor = topColor
            setGradient()
        }
    }
    @IBInspectable var bottomColor: UIColor? {
        didSet {
            toColor = bottomColor
            setGradient()
        }
    }
    
    
    func setGradient() {
        
 
        let gradientLocations = [0.0,1.0]
        let gradientLayer = CAGradientLayer()
        if fromColor != nil && toColor != nil
        {
            gradientLayer.colors = [fromColor!.cgColor, toColor!.cgColor]
        }
        
        gradientLayer.locations = gradientLocations as [NSNumber]
        
        gradientLayer.frame = self.bounds
        self.layer.insertSublayer(gradientLayer, at: 0)

        

    }
    
}